Role of Hypertension as a Major Risk Factor of Stroke in Africa; Libya: Community Based Survey

Hypertension is a very common medical disorder and a major health problem in North Africa. Hypertension is associated with an increase in the risk of stroke and hospitalization.

Objectives: To estimate the importance of hypertension (HT) as a stroke predisposing risk factor among people living in Libyan community using both CHADS2 and Community Stroke Risk Classification (CSRC).

Methodology: Area; North Africa (North of Libya, the capital Tripoli). Time; Five years from 2010-2014.

The study was a community based descriptive cross-section, which screened 7497 individuals living in local communities, looking for risk factors of stroke. Hypertension was one of the factors which was studied in details by community physicians, among this population whom have HT were diagnosed by their past histories, medical reports, hospital discharge letters, whether they were taking any treatment or on a diet for hypertension and also medical examinations were conducted to confirm diagnosis by measuring blood pressures.

Results: The prevalence of HT among study participants (7497 individuals) was 38% (2850 patients), among males and females was 50.2% and 49.8% respectively (P =0.041). Among different age groups, males had higher rates than females except for age intervals of 50-59 and ≥80 where females had higher rates. The male to female ratio among the total population screened was almost similar (19%: 18.9%).

HT prevalence rose with the increase of age, with higher rates among age groups of over 40 (P <0.0001).

53% of hypertensive patients had: Diabetes Mellitus (DM) (1538 patients), 27.3% had Congestive Heart Failure (CHF) (778 patients), 15.6% had Atrial Fibrillation (AF) (446 patients), 26.7% had Transient Ischemic attack (TIA) (761 patients), and 14.8% had prior stroke (PS) (423 patients), All these risk factors accompanying hypertension rose with increase of age (P<0.0001).

99.9% of hypertensive patients had risk points of stroke on the CHADS2 scoring system (0.1% had no risk points), from that 53% had intermediate scores (1-2 Risk Points) and 47% had high scores (≥3 risk points).

Results of CSRC score showed that 99.9% of hypertensive patients had risk factors of stroke (0.1% had no risk factors), from whom 56% had intermediate scores (1-2 Risk Factors) and 54% had high scores (≥3 risk factors).

Conclusion: Hypertension is a major risk factor of stroke among the North African Libyan population and many, of whom have HT, had very high risk scores in CHADS2 which mainly concentrates on 1-6 risk points (P<0.0001). Almost all hypertensive patients had risk factors of stroke on CSRC scores which was generally contributed to intermediate and high scores. CHADS2 & CSRC classification scores are very useful tools to be used to classify and describe the risk factors of stroke in a population of a community regardless of having hypertension or not.